Visceral fat tissue is an important predictor of cardio-metabolic disease, carrying more risk than general fat accumulation.
Metabolically deleterious and life threatening forms of obesity associate with accumulation of fat in the visceral adipose tissue and ectopic fat deposition in organs (Graner et al. (2013), 98: 1189-1197; Donahue and Abbott, (1987), Lancet 2: 1215; Kalkhoff et al. (1983), J Lab Clin Med 102: 621-627. In particular, higher visceral adiposity (VA) links to a higher probability of developing atherosclerotic cardiovascular diseases mediated via complex signaling metabolic functions that interplay with the endocrine and immune system (Batra and Siegmund, (2012), Dig Dis 30: 70-74; Fox et al. (2007), Circulation 116: 39-48).
Visceral fat includes a complex topographical fat deposition, namely mesenteric and epicardial adipose tissue, as well as peripheral depots around other organs (Dulloo et al. (2010), Int J Obes (Lond) 34 Suppl 2: S1-S3). The distinct metabolic differences existing between these visceral tissues result in specific contribution to disease etiologies.
Epicardial adipose tissue (EAT) is a particular form of visceral fat deposited around the heart. It is present on the surface of the heart between the myocardium and visceral pericardium and covers a significant surface of the heart.
An increase of the quantity of EAT is associated with incident coronary artery disease and with major adverse cardiac events (Mahabadi et al., 2013, J Am Coll Cardiol. 2013 Apr. 2; 61(13):1388-95) In particular, epicardial adipose tissue has a strong correlation with atherosclerosis, metabolic syndrome, impaired fasting glucose, insulin resistance, hypertension and diabetes mellitus.
Indeed, an increasing interest for general public health points towards childhood growth and obesity, where EAT is known as a major predictor for metabolic health.
It has also been shown that patients with psoriasis have a higher level epicardial fat compared with controls (Balci et al. 2013 Oct. 25, CED, 12216).
Epicardial adipose tissue can be measured by a number of imaging techniques including echocardiography, computer tomography (CT) and magnetic resonance imaging (MRI). However, such methods can be time consuming, expensive and are not appropriate for routine use.
Recent applications have demonstrated the feasibility of associating specific metabolite profiles to body fat distribution (Szymanska et al. (2012) OMICS 16: 652-667; Yamakado et al. (2012), Clinical Obesity 2: 29-40) including amino acids and various lipid species (triacylgylcerols, diacylglycerols, lysophospholipids, sphingomyelins, ceramides). However, markers associated with epicardial fat have not been identified.
Consequently, it was the objective of the present invention to provide lipid biomarkers that can be detected easily and that facilitate the prediction of EAT. Such lipid biomarkers can be used to promote healthy living by identifying subjects in need of reducing levels of EAT, and modifying the lifestyle of such subjects accordingly.